Detection and sizing of wall thickness loss by Digital Radiography

Topic :

Non-Destructive Examination methods

ABSTRACT :

The use of classical radiography is commonly used to identify Wall thickness loss in pipe elemnts. If a wall thickness loss is observed, the thickness is often verified by ultrasound transducers because of the difficulty to evaluate the wall thickness correctly on the film.
The use of digital radiography makes it possible to detect and measure wall thickness loss directly on the digital image.

SInce 2005, EDF/DTG works on the evaluation of the use of Digital Radiography for wall thickness measurements. The method that was evaluated by EDF/DTG is the tangential projection method and the measurement of the projected pipe wall.
Digital radiography, was evaluated in a large scale test program including test on artificial and real defects. The conclusions of the test were presented in early 2009 and the method is used since on the EDF fleet in 2010.

The presentation will recall the validation method, the final results in terms of precision and limitaions regarding different source types, and indicate how to use this technique on site.

Speaker Biographical Information

Thomas Knook works at EDF/DTG since 1999, where he is in charge for testing and qualification of new NDE techniques related to FAC. Before he came to EDF/DTG heworked from 1986 to 1999 for the German utility RWE in the fast breeder nuclear power plant called Superphenix. At the SPX powerplant he was in charge for the in-service inspection of the reactor vessel and the secondary sodium loops.